U.S. and European Union representatives asked Tuesday for increased cooperation in the response to Europe’s refugee crisis.

The officials, appearing on Capitol Hill in Washington, downplayed security concerns expressed by members of the Commission on Security and Cooperation in Europe, an independent, bipartisan federal agency that monitors compliance with the Helsinki Accords and works to advance comprehensive global security.

The commission chairman, U.S. Representative Christopher Smith, a New Jersey Republican, called the Syrian crisis the biggest refugee crisis in Europe since World War II. He said it required “a response that is European, national and international, and the United States is essential to it.”

But Smith and other members of the commission expressed concerns about the potential national security implications of allowing refugees from the Middle East into the United States.

“No one comes in" if safety questions exist, Anne Richard, U.S. assistant secretary of state for population, refugees and migration, said in her testimony on the U.S. government response to the refugee crisis.

Richard said 14,000 refugees of the 22,000 being processed were awaiting interviews with the Department of Homeland Security, adding that DHS was feeling pressure to add personnel and resources to speed processing times.

But even with limited personnel to meet the unprecedented demand, Richard said she remained confident in the security of the vetting process for letting refugees into the United States.

“Europe is debating, but the U.S. is very much doing,” Richard said of the wider U.S. government response.

Richard said the Obama administration aims to bring in 10,000 Syrian refugees of the 85,000 refugees projected to be brought into the United States in 2016. Fewer than 2,000 Syrian refugees have arrived in the United States in 2015.

David O’Sullivan, the European Union ambassador to the United States, echoed those reassurances, saying he was “not surprised that it’s young, fit men who felt able to make the journey rather than families with children.”

He added that there were easier ways for terrorists to get into Europe and the United States than to submit to being fingerprinted and photographed.

According to the U.N. refugee agency, more than 635,000 refugees and migrants arrived in Europe by sea this year. More than half of those refugees came from Syria, source of the largest refugee population in the world.

Katherine Gypson is a reporter for VOA’s News Center in Washington, D.C. Prior to joining VOA in 2013, Katherine produced documentary and public affairs programming in Afghanistan, Tunisia and Turkey. She also produced and co-wrote a 12-episode road-trip series for Pakistani television exploring the United States during the 2012 presidential election. She holds a Master’s degree in Journalism from American University. Follow her @kgyp